PERTH, March 31 Australian Prime Minister Tony
Abbott said on Monday the hunt for Malaysia Airlines Flight
MH370 had no time limit, despite the failure of an
international operation to find any sign of the plane in three
weeks of fruitless searching.

A total of 20 aircraft and ships were again scouring a
massive area in the Indian Ocean some 2,000 km (1,200 miles)
west of Perth, where investigators believe the Boeing 777
carrying 239 people came down.

"I'm certainly not putting a time limit on it," Abbott told
reporters after meeting flight crews at Pearce airbase in Perth.

"The intensity of our search and the magnitude of our
operations is increasing, not decreasing," he said, adding that
searchers owed it to grieving families of passengers to continue
the hunt.

Some families have strongly criticised Malaysia's handling
of the search and investigation, including the decision last
week to say that, based on satellite evidence, the plane had
crashed in the southern Indian Ocean on March 8.

Abbott rejected suggestions his Malaysian counterpart, Najib
Razak, had been too hasty to break that news, given that no
confirmed wreckage from the plane has been found and its last
sighting on radar was northwest of Malaysia heading towards
India.

"No, the accumulation of evidence is that the aircraft has
been lost and it has been lost somewhere in the south of the
Indian Ocean," he said.

Najib will travel to the western Australian city of Perth,
the base for the search, on Wednesday to see the operations
first hand, Malaysia's government said.

Malaysia says the plane, which disappeared less than an hour
into a flight from Kuala Lumpur to Beijing, was likely diverted
deliberately far off course. Investigators have determined no
apparent motive or other red flags among the 227 passengers or
the 12 crew.

China has also been critical in Malaysia's handling of the
case, but in a sign of softening, the official China Daily said
it was understandable that not all sensitive information could
be made public.

"Although the Malaysian government's handling of the crisis
has been quite clumsy, we need to understand that this is
perhaps the most bizarre incident in Asia civil aviation
history," the editorial on Monday read.

"Public opinion should not blame the Malaysian authorities
for deliberately covering up information in the absence of hard
evidence."

MORE FLOTSAM

Dozens of items have been spotted since Australian
authorities moved the search 1,100 km (685 miles) north after
new analysis of radar and satellite data, but none has been
linked to Flight MH370.

Several orange items recovered on Sunday turned out to be
fishing equipment, a spokesman from the Australian Maritime
Safety Authority (AMSA) said.

"Yesterday's finds were nothing of note, nothing related to
the plane," he said.

A multinational air search team and 10 ships, including
seven Chinese vessels, two Australian navy craft and a merchant
ship, were searching the area on Monday.

A Malaysian frigate arrived at HMAS Stirling naval base near
Perth for briefings on the search area, AMSA added.

The new search area, while closer to Perth and subject to
calmer weather, is also closer to an area of the Indian Ocean
where currents drag all manner of flotsam and rubbish.

"I would say the search area is located just outside of what
we call the garbage patches," Erik van Sebille, an oceanographer
at the University of New South Wales said.

"However, there is much more debris there than in the
Southern Ocean. Debris from Western Australia that ends up in
the garbage patches will have to move through the search area."

But the greatest problem remains the vast search area,
roughly the size of Poland or New Mexico.

"If you compare this to Air France Flight 447, we had much
better positional information of where that aircraft went into
the water," U.S. Navy Captain Mark Matthews said on Sunday ,
referring to a plane that crashed in 2009 near Brazil and which
took more than two years to find.

Among the vessels due to join the search in the coming days
is an Australian defence force ship, the Ocean Shield, that has
been fitted with a sophisticated U.S. black box locator and an
underwater drone.

That equipment cannot be used until "conclusive visual
evidence" of debris is found, U.S. Navy spokesman Commander
William Marks told CBS's "Face the Nation" programme.

If no location is found, searchers would have to use sonar
to methodically map the bottom of the ocean, he said. "That is
an incredibly long process to go through. It is possible, but it
could take quite a while," he said.

Time is running out because the signal transmitted by the
black box will die about 30 days after a crash due to limited
battery life, leaving investigators with a vastly more difficult
task.

Malaysia's acting transport minister, Hishammuddin Hussein,
said he would discuss the deployment of "more specific military
assets" during a regional defence ministers' meeting with the
United States in Hawaii that he is attending from Tuesday.

"I shall be discussing with the United States, and our other
friends and allies, how best we can acquire the assets needed
for possible deep sea search and recovery," said Hishammuddin,
who is also Malaysia's defence minister.
(Additional reporting by Morag MacKinnon and Matt Siegel in
Perth, Jane Wardell and Lincoln Feast in Sydney, Adam Jourdan in
Shanghai and Andrea Shalal in Washington; Writing by Lincoln
Feast; Editing by Alex Richardson)

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